Light sheet fluorescence microscopy or selective plane illumination microscopy (SPIM) technology typically relies on illuminating a sample in thin optical slices, formed from laser light, exciting the fluorophores in the sample and acquiring light emitted by the illuminated plane inside the sample. The direction in which the light is detected is typically perpendicular to the illuminated plane.
With SPIM, the lateral resolution is determined by the detection objective lens and the axial resolution is related to the numerical aperture (NA) of the illumination objective. With low NAs, the Z resolution is determined by the thickness of the light sheet, with an excellent isotropic Point Spread Function. With higher NAs, the axial resolution is similar to confocal fluorescence microscopes. Images from light sheet microscopes exhibit a better signal-to-noise (S/N) ratio and a higher dynamic range than images produced by confocal fluorescence microscopes.
Typically, standalone light sheet fluorescence microscopes are costly and take up a considerable amount of valuable physical space in a laboratory. Additionally, current techniques to hold samples for SPIM limit the type and range of samples that can be observed using SPIM.